220 research outputs found
Isolation and characterization of l-methionine-resistant mutants of sv40-transformed balb 3t3 (svt2) affecting l-meth- ionine transport.
MUTATION TO l-RHAMNOSE RESISTANCE AND TRANSDUCTION TO l-RHAMNOSE UTILIZATION IN SALMONELLA TYPHOSA,
Salmonella typhosa is unable to utilize L-rhamnose as a carbon and energy source for growth. When rhamnose is added to a nutrient agar medium (or other similar media), which otherwise supports growth of this organism, growth is reportedly partially inhibited, and rhamnose resistant papillae arise (Muller, 1911). These mutants, which are no longer inhibited by rhamnose, and which no longer papillate on rhamnose nutrient agar, are still similar to the parent strain in being unable to utilize rhamnose as a carbon and energy source, produce acid or gas from rhamnose, or oxidize rhamnose (Mutller, 1911; Barkulis, 1949). Thus this mutational phenomenon differs from that of Escherichia coli mutabile, where papillae formed on lactose media produce acid and gas from lactose and utilize lactose as a carbon and energy source. Salmonella typhimurium, on the other hand, is able to utilize rhamnose as a carbon and energ
Recessive constitutive mutant Chinese hamster ovary cells (CHO-K1) with an altered A system for amino acid transport and the mechanism of gene regulation of the A system.
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